"""
author:dlr123
date:2021年11月30日
"""
import matplotlib.pyplot as plt
import numpy as np
import pandas as pd
def f(data):
    A = 10
    return 10*A + data ** 2 - A*np.cos(2*np.pi*data)
if __name__ == '__main__' :
    data = np.linspace(-1,1,21)
    s = pd.Series(data)
    print(s)
    plt.plot(data,f(data))
    plt.show()
    